Fetter Lane, London
Low Carbon Emission Readings Influence Choice of Daikin VRV Air Conditioning for Major City Office Development
_tcm46-84808.jpg "Fetter lane, London(1)")
State of the art Daikin inverter controlled VRV heat recovery air conditioning is a key component of new building services designed by consultants Foreman Roberts, London SE1, for the 15 Fetter Lane, EC4, development. Rising phoenix like from its former site, the new complex is among the more imaginative and visually attractive additions to the City’s commercial office stock.
The redevelopment of the site by the British Steel Pension Fund has seen the earlier building stripped back to its shell and rebuilt to Grade A specification, offering 70,000ft2 of open plan office accommodation on 9 floors.
Installed by Daikin D1 installers, Breathe Air, Cambridge, and commissioned by mechanical and electrical contractors, EMCOR, for consultants Foreman Roberts, the new air conditioning system comprises 33 REYQ VRV heat recovery systems. These supply 220 FXYSM fan coil units, located within the false ceilings on each floor and ducted to linear grilles around the ceiling perimeter and central core of the building. Indoor design temperature is set at 21° C +/- 2 deg C, summer and winter.
Each floor is divided into 3 zones, each zone being handled by its own VRV system and when tenanted, its own Daikin I-controller, allowing the landlord to monitor electrical consumption and apportion its costs on an individual tenant basis.
Each floor is also supplied with heat recovery ventilation via 5 or 6 Daikin VAM units, also located in the floors’ false ceilings. _tcm46-84810.jpg "Fetter lane, London(2)")
Tempered fresh air is supplied by these units, which modulate the temperature and humidity of incoming outdoor air to match prevailing indoor conditions. A balance is thereby achieved between indoor and outdoor ambient conditions, minimising the loading imposed on the air conditioning system to cool or heat the incoming air. The high sensible and latent heat reclaim features inherent in VAM units reduce input energy requirements and costs and keep CO² emissions to a minimum.
Overall VRV and VAM control is provided by a Daikin i-manager located in the ground floor control room, which will, if the central computer crashes, continue its control and management functions for not less than 48 hours.
I-Manager is a dedicated centralised system ensuring maximum energy efficient operation of the VRV systems. Like I-controller, it uses the Daikin DIII-Net high speed, multi transmission, data communication system to ensure precise monitoring and control. It communicates with the security and safety systems that control automatic locking of the on/off function of the air conditioning units and limits energy consumption, indicates filter replacement periods, optimum start up times and a variety of dedicated management and service functions.
Key decisions behind the consultants’ choice of VRV air conditioning included the system’s favourable carbon emission readings compared to those of a similar capacity chilled water system, which could not have satisfied Part L regulations on this particular installation. Also, the VRV system’s inherent design and installation flexibility overcame the building’s lack of plant room spa.
